Electric control valve



July 4, 1967 ELECTRI C CONTROL VALVE Filed April 24, 1964 V. L. FR'ANTZ FIG. 5

Inventor:

Virgil L. Frantz his Attorney United States Patent O 3,329,392 ELECTRIC CONTROL VALVE Virgil L. Frantz, Salem, Va., assgnor to Graham-White Sales Corporation, Salem, Va., a corporation of Virginia Filed Apr. 24, 1964, Ser. No. 362,366 2 Claims. (Cl. 251-30) This invention relates to electric control valves for controlling the flow of air to associated air operated devices.

The primary object of the invention -is to provide an electric ycontrol valve which, while controlling the flow of operating air to one or more associa-ted devices by an air actuated differential piston, requires but a single inlet line from a reservoir or other source of compressed air for both operating and actuating air.

Another object of the invention lis to provide an electric control valve which Inot only possesses the above characteristics but has its parts so arranged and constructed as to ensure that any dirt, oil or other foreign matter, introduced with the actuating air, will be discharged at the end of each operation.

Other objects and advantages of the invention will appear hereinafter in the detailed description, be particularly pointed out in the appended claims and be illustrated in the accompanying drawings, in which:

FIGURE 1 is a side elevational view of a preferred embodiment of the electric control valve of the present invention, with a portion shown .in section to more clearly illustrate certain of the details of construction;

FIGURE 2 is a vertical sectional view taken along lines 2 2 of FIGURE l; and

FIGURE 3 is a fragmentary sectional view on an enlarged scale and on the plane of the sectioned portion of FIGURE 1, showing the connection between the inlet port and the inlet passage for actuating air.

Referring now in detail to the drawings in which like reference characters `designate like parts, the improved electric control valve of the present invention -is adapted to control the operation of one or more air operated devices and .is designed for installations in which, as in a diesel locomotive, there are a number of such devices and it is advantageous to reduce the required piping to a minimum. The improved valve also is particularly suited for installations in which it is desired that air operated devices operate automatically under predetermined conditions.

The basic components or parts of the improved electric control valve are a body or casing 1, an air actuated differential piston 2 contained in the body for controlling the iiow of operating air to one or more air operated devices, an electrically responsive pilot valve 3 mounted on the body for controlling the liow of actuating air to the piston, and a common or single inlet 4 for both operat-ing and actuating air which is connectable by a single line to a reservoir or other suitable compressed air source (not shown).

.In illustrating the invention, the above basic components have been embodied in an electric sander control valve installable on a diesel locomotive for controll-ing the oper-ation of a pair of Sanders or san-d traps by which sand is applied -to the rails for increased traction. The illustrated valve has its body or casing 1 divided or split along a joint or part line 5 into a mounting bracket 6 containing or mounting the common inlet or inlet port 4 and an outlet port 7 for each sander (not shown), and a housing or body 8 containing or mounting the operating parts, including the piston 2 and the pilot valve 3. The mounting bracket 6 is permanently mountable on a suitable support (not shown) and the housing 8 is Y bolted or otherwise releasably attached or connected to .3,329,392 Patented July 4, 1967 ICC or mounted on the mounting bracket Afor removal for repair or replacement of the operating parts without dis-YA turbing permanent pipe connections (not sho-wn) to the ports 4 and 7 in or on the bracket.

In accordance with usual practice, the illustrated con trol valve is adapted in a sanding operation to supplyV initial and final clean-out blasts and intervening relatively low pressure sanding air to each sander from one of the outlet ports 7 through a single outlet line (not shown). Except that they preferably are inverted, the piston and housing structure directly responsible for this sequential supply are similar to the standard air operated sander control valve of my Patent No. 2,589,794 of Mar. 18,`

1952, as modified in my copending application Ser. No. 258,050, filed on Feb. 12,v 1963. Thus, the vertically shiftable or reciprocable differential piston 2 has a large, lower hea-d 9 slidable in ya lower cylinder 10 and relat-ively small upper and intermediate heads 11 and 12, respectively, spaced and connected by a stem 13. The upper head 11 is contained in an upper cylinder or cavity 14 and the intermediate head 12 slides in a valve chamber 15 between the cylinders.

Oppositely facing upper and lower valve seats 16 and 17 are formed in the housing 8, respectively at the upper end and intermediate the ends of the valve chamber 15. In the normal Closed condition of the control valve, the upper head or valve element 11 seats in and closes the upper seat 16 under force of a return spring 18 acting between the head and a top cap 19 closin-g the upper end of the housing S. While normally spaced therebelow, the intermediate head or lower valve element 12 seats in and closes the lower seat 17 in the open condition of the valve. A pair of orifices for each sander open.

on-to the valve chamber 1S, one, a clean-ou-t orifice 20,.

between the lower seat 17 and the intermediate head 12 in the latters normal position and the other, a relatively restricted sanding orifice 21, between the two seats. Each. pair of orifices 20 and 21 connects through a common shown) and the relative areas of .the upper and lower heads 14 and 10 and the strength of the return spring; 18 are such that air for actuating the piston 2 can be.v

supplied to the lower cylinder 10 below the lower headl 9 from the same source and at the same pressure as the operating air. Upward shifting or displacement of the piston 2 under force of the actuating air will close the lower seat 17 and block operating air from the cleanout orifices 20 but permit that air under reduced pres;` sure to ow, as sanding air, to the outlet ports 7. However, during the short intervals in which both seats 16 and 17 are open, as the piston 2 moves between closed and open positions, the clean-out orifices 20 will also .v

be open to operating air and thus permit the initial and final clean-out blasts to be supplied to the sand traps.

Control of the iiow of actuating air to the lower cylinder 10 for in turn controlling by the piston 2 the flow of operating air to the Sanders, is the function of the electrically responsive pilot or solenoid valve 3. Prefer-v ably suspended from the housing 8, conveniently by having its body formed as a central plug 24 screwed orv threaded from below into a bottom cap 25 on the housing closing the lower end of the lower cylinder 10, the solenoid valve 3 has a vertically disposed coil pole 26 concentric or coaxial with and screwed at its upper end into the bottom plug 24. The coil 27 and its case 28 are held on the coil pole 26 by a cap nut 29.

upper 'cylinder 14 from a reservoir or other suitable source (not A vertical axial bore 30 contained in part in the coil pole 26 and in balance in the plug 24, slidably receives anl axially shiftable or reciprocable plunger 31. The plunger 31 preferably lis of the same construction as hat of my Patent No. 2,887,126 of May 19, 1959, with Flats 32 on its side to pass air around it through the )ore 30 and rubber pads 33 in its ends for alternatively :losing upper and lower valve or plunger seats 34 and 55 Yat upper and lower ends, respectively, of the bore. Ihe lower seat 35 -is at the upper end of an exhaust nassage 36 yleading downwardly through the coil pole Z6 to an exhaust port 37 in the cap nut 29. In its turn, :he upper seat 34 is at the inner end of an actuating air nlet passage 38 having an outer leg 39 crossing the joint and connecting to an annular groove 40 in the bottom :ap 25 about the plug 24. The inner part of the inlet ,Jassage 38 conveniently is a bent leg 41 connecting to :he groove 40 and extending radially and axially through :he plug 24 to the upper seat 34. The upper end of the )ore 30 around or outside the upper seat 34 is open at ill times to or in constant communication with the ower end of the lower cylinder through a connectng passage or aperture 42 extending vertically through :he intervening part of the plug 24 and eccentric to or )iTset laterally or radially from the upper seat.

While actuating air at the same pressure and from the- ;ame source as the operating air is intended always to be available in the inlet passage 38, access of that air `:hrough the bore 30 and connecting passage 42 to the lower cylinder, normally will be blocked by closing of the upper seat 34 by the plunger 31 under force of a spring 43 acting between an upper end flange 44 on the plunger and an upper end of the coil pole 26. However, energizing of the coil 27 will retract the plunger against the lower seat 35, closing the exhaust passage 36 and exposing the lower head 9 of the piston 2 to actuating air from the inlet passage 38, whereupon the piston will shift to Open position and the sanding operation will proceed. Conversely, deenergizing of the coil 27, by permitting the spring 43 to return the plunger-31 to normal position, will close the inlet passage 38 and open the exhaust passage 36. At that time the residual compressed air in the lower cylinder 10 below the lower head 9 will be exhausted or bled to atmosphere through the connecting passage or port 42, the bore 30 around the plunger 31, the exhaust passage 36 and, finally, the exhaust port 37. At the same time, the downward route of the exhausting air, in the preferred vertical mounting of the solenoid valve 3 on the bottom of the housing 8, by enabling gravity to assist rather than oppose the tiow of the residual compressed air, ensures that any dirt, oil or other foreign matter trapped in the lower cylinder 10 during operation of the control valve, will be discharged, removed or exhausted with the exhausting air at the end of that operation. Although not of prime importance in the preferred construction, entry of foreign matter into the lower cylinder 10 can be restricted, if desired, by placing a strainer plug 45 in the outer leg 39 of the inlet passage 38 and conveniently over the joint S so that the plug is readily accessible for cleaning.

An important aspect of the valve of the present invention is the control it permits of the rate of movement of the piston 2 between open and closed positions which in turn controls the duration of the initial and final clean lout blasts in a sanding operation. If the port or bore 46' in the strainer plug 45, the two way, connecting passage 42 and the exhaust port 37 were all of Ms or other diameter suitable to pass air without substantial choking or reduction in pressure and thus in effect wide open, the piston would move so rapidly that the initial and iinal blasts would be too short to be effective. Choking at the plug port 46 would slow the opening but not the closing of the piston 2 and would also run the risk of insuicient pressure beyond that port to assist in retracting 32 on energizing of the coil 27. However, it has been found feasible to slow both the opening and the closing of the piston to any desired rate and without impairment of the intended operation of the valve by choking at the connecting port 42. The preferred rate, comparable with that obtained with a conventional, airactuated sander control valve, is obtained by restricting the connecting passage 42 to a diameter of about .0215". A one way passage of such small diameter would be subject to clogging but, even when restricted to this small diameter, the two way or breathing passage has been found to be kept clean or free and be in eiect self-cleaning by the bi-directional air passing through it.

Responsive in its operation to energizing of the coil 27 of its solenoid valve 3, the improved control valve is operated by a switch (not shown) wired in series with the coil and, as desired, the switch can be suited either for manual operation at a cab or other convenient location or for automatic operation on sensing of a predetermined condition, such as wheel slippage. Another and quite important aspect of the improved valve, particularly in diesel locomotive and like installations in which any reduction in the complex piping required for the various air operated devices is highly desirable, results from its ability to operate with operating and actuating air introduced at the same pressure and its need for no extraneous valving. This is its provision with the angle or common inlet port 4 connectable by a single line (not shown) to a suitable compressed air source for supplying the operating air to the upper cylinder 14 and the actuating air to the inlet passage 38. In the case of the illustrated sander control valve, this permits the elimination of one of the two separate air lines heretofore customary in bringing operating and actuating air to such a valve.

As desired, the inlet port 4 and passages 47 and 38 leading therefrom to the upper and lower cylinders 14 and 10, can either be mounted on or, as illustrated, inbuilt into the body 1 of the valve. In the illustrated inbuilt construction, the inlet port 4 conveniently is vertically directed and formed in and substantially centered laterally on the underside 46 of the mounting bracket 6. The operating air inlet passage 47 leading from the inlet port to the upper cylinder 14 has a vertically directed outer leg 48 formed in the mounting bracket 6 and aligned with and extending upwardly from the port inlet port 4 to the upper cylinder 14 has a vertically directed inner leg 49 crossing the joint 5 and opening inwardly onto the upper cylinder 14. The outer leg 48 opens downwardly onto a chamber 50 of larger crosssection interposed between it and the port 4 and the connection of the outer leg 39 of the actuating air inlet passage 38 to the port is made through the same chamber, As indicated, the relatively moving and movable parts of the control valve are suitably sealed against leakage of actuating and operating air to ensure its eicient operation.

From the above detailed description it will be apparent that there has been provided an improved electric control valve which requires a minimum of piping and in its preferred form is also self-cleaning. It should be understood that the described and disclosed embodiment is merely exemplary of the invention and that all modications are intended to be included that do not depart from the spirit of the invention or the scope of the appended claims.

Having described my invention, I claim:

1. An electric control valve comprising a body, a cavity in said body, a cylinder in said body below and connected by a valve chamber to said cavity, outlet port means in said body and communicable with said cavity through said valve chamber, said body having a single air inlet connectable to a compresed air source and separate inlet passages leading from said inlet for supplying at the same pressure operating air and acutating air respectively to said cavity and cylinder, an air actuated differential piston reciprocable vertically in said body and having a large head slidably received in said cylinder and a small head connected for movement in unison to said large head and contained in said cavity and normally blocking flow of operating air therefrom to said outlet port means, and a vertically disposed solenoid valve unit screwed from below into a bottom of said body below said cylinder, said solenoid valve unit having therein an inlet passage directly connected to said actuating air inlet passage in said body for passing actuating air at said same pressure, an exhaust passage leading downwardly past a plunger thereof to an exhaust port opening downwardly to the exterior of said solenoid valve unit, and a vertically directed connecting passage in said unit opening upwardly into said cylinder for alternately connecting said cylinder to said inlet passage and through said exhaust passage to `said exhaust port, said connecting passage on connection to said inlet passage passing actuating air at said same pressure to said cylinder and on connection to said exhaust port being assisted by gravity in passing from said cylinder air and matter condensed therefrom.

2. An electric control Valve according to claim 1, wherein the connecting passage is restricted relative to the inlet passage in said unit for delaying the build-up of actuating air at said same pressure in said cylinder and thereby delaying actuation of the piston in resopnse to the actuating air.

References Cited UNITED STATES PATENTS 2,589,794 3/ 1952 Frantz 251-63 X 2,664,916 l/1954 Conley 251--30 X 2,698,729 1/ 1955 `Cox et al 251-25 3,110,468 11/1963 Herion 251-30 X 3,176,954 4/1965 Cameron et al. 251--30 X -M. CARY NELSON, Primary Examiner. ARNOLD RosENTHAL, Examiner. 

1. AN ELECTRIC CONTROL VALVE COMPRISING A BODY, A CAVITY IN SAID BODY, A CYLINDER IN SAID BODY BELOW AND CONNECTGED BY A VALVE CHAMBER TO SAID CAVITY, OUTLET PORT MEANS IN SAID BODY AND COMMUNICABLE WITH SAID CAVITY THROUGH SAID VALVE CHAMBER, SAID BODY HAVING A SINGLE AIR INLET CONNECTABLE TO A COMPRESED AIR SOURCE AND SEPARATE INLET PASSAGES LEADING FROM SAID INLET FOR SUPPLYING AT THE SAME PRESSURE OPERATING AIR AND ACUTATING AIR RESPECTIVELY TO SAID CAVITY AND CYLINDER, AN AIR ACTUATED DIFFERENTIAL PISTON RECIPROCABLE VERTICALLY IN SAID BODY AND HAVING A LARGE HEAD SLIDABLY RECEIVED IN SAID CYLINDER AND A SMALL HEAD CONNECTED FOR MOVEMENT IN UNISON TO SAID LARGE HEAD AND CONTAINED IN SAID CAVITY AND NORMALLY BLOCKING FLOW OF OPERATING AIR THEREFROM TO SAID OUTLET PORT MEANS, AND A VERTICALLY DISPOSED SOLENOID VALVE UNIT SCREWED FROM BELOW INTO A BOTTOM OF SAID BODY BELOW SAID CYLINDER, SAID SOLENOID VALVE UNIT HAVING THEREIN AN INLET PASSAGE DIRECTLY CONNECTED TO SAID ACTUATING AIR INLET PASSAGE IN SAID BODY FOR PASSING ACTUATING AIR AT SAID SAME PRESSURE, AN EXHAUST PASSAGE LEADING DOWNWARDLY PAST A PLUNGER THEREOF TO AN EXHAUST PORT OPENING DOWNWARDLY TO THE EXTERIOR OF SAID SOLENOID VALVE UNIT, AND A VERTICALLY DIRECTED CONNECTING PASSAGE IN SAID UNIT OPENING UPWARDLY INTO SAID CYLINDER FOR ALTERNATELY CONNECTING SAID CYLINDER TO SAID INLET PASSAGE AND THROUGH SAID EXHAUST PASSAGE TO SAID EXHAUST PORT, SAID CONNECTING PASSAGE ON CONNECTION TO SAID INLET PASSAGE PASSING ACTUATING AIR AT SAID SAME PRESSURE TO SAID CYLINDER AND ON CONNECTION TO SAID EXHAUST PORT BEING ASSISTED BY GRAVITY IN PASSING FROM SAID CYLINDER AIR AND MATTER CONDENSED THEREFROM. 